The present invention relates to a method and an apparatus for manufacturing a specific injection needle comprising a hub and a cannula, in which the cannula has a front end projecting from the hub and a back end terminating within the hub.
Conventional injection needles include, as one type, the specific injection needle such as one called "insulin needle" available from Novo Nordisk A/S, which has a specific structure and configuration wherein a cannula having a front end with a sharp bevel and a back end with another sharp bevel inserts in a center hole of a hub in such a manner that the back end projecting inside the hub terminates within the hub (hereinafter, this type of injection needle is merely referred to as injection needle).
The injection needle comprises the cannula and the hub. The cannula of a hub-cannula assembly is covered with a cap, and thereafter the hub- cannula-cap assembly is housed in a hermetically sealed container for subsequent further handling.
One example of the injection needle is illustrated in FIG. 2.
In the injection needle 1 of FIG. 2, a cannula 11 having a front end 13 with a sharp bevel and a back end 14 with another sharp bevel inserts in a center hole of a hub 12 in such a manner that the back end 14 projecting inside the hub 12 terminates within the hub 12.
The hub 12 of the injection needle 1 of FIG. 2 has a bonding area around the center hole for bonding with the cannula 11. The bonding area projects from the rest part of the hub 12 to form a protrusion 12a. The exposed part of the cannula 11 is to be covered by a cap 10 of an elongated cylindrical shape which has an open end 10a and a semi-spherical closed end 10b and is so designed that the open end 10a can be engaged with the protrusion 12a.
The injection needle 1 whose front end 13 has been thus covered with the cap 10 (hub-cannula- cap assembly) is then housed in a container 30 having an opening at one end, and thereafter the opening of the container 30 is sealed with a piece of sealing sheet 31 by means of, for example, heat-sealing.
A process of manufacturing the injection needle 1 should include at least the following work steps or the like:
(a) Adhering the cannula 11 to the hub 12. PA1 (b) Applying silicone oil (hereinafter referred to simply as silicone) to the front end 13 and the back end 14 of the cannula 11 for the purpose of reduction of penetration force. PA1 (c) Covering the front end 13 with the cap 10. PA1 (d) Housing the hub-cannula-cap assembly into the container 30. PA1 (e) Sealing the opening of the container 30 with the sealing sheet 31. PA1 (a) mounting the hub on a first subassembly jig capable of supporting individually the hub and the cannula in predetermined positions relative to each other, with the front end of the cannula pointed upward; PA1 (b) inserting the cannula into the center hole of the hub to a depth limited by the first subassembly jig; PA1 (c) applying an adhesive to a bonding area of the hub and the cannula; PA1 (d) curing the adhesive in the bonding area to form a hub-cannula assembly; PA1 (e) dismounting the hub-cannula assembly from the first subassembly jig; PA1 (f) applying silicone-containing-liquid to the back end of the cannula of the hub-cannula assembly; PA1 (g) mounting the hub-cannula assembly, whose back end has been coated with silicone-containing-liquid, on a second subassembly jig having a hollow cylindrical rest capable of supporting the hub-cannula assembly by contacting only the hub, with the front end of the cannula pointed upward; PA1 (h) removing excess amount of silicone-containing-liquid remaining within the cannula; PA1 (i) applying silicone-containing-liquid to the front end of the cannula of the hub-cannula assembly; PA1 (j) covering the front end of the cannula with a cap of an elongated cylindrical shape having an open end and a semi-spherical closed end to form a hub-cannula-cap assembly; PA1 (k) housing the hub-cannula-cap assembly into a container having an opening at one end to form a hub-cannula-cap-container assembly; PA1 (l) dismounting the hub-cannula-cap-container assembly from the second subassembly jig; and PA1 (m) sealing the opening of the container of the hub-cannula-cap-container assembly. PA1 (a) a first subassembly jig having a hub-supporting portion and a cannula-supporting portion and being capable of supporting individually plural pairs of the hub and the cannula in one line in such a manner that the hub and the cannula are in predetermined positions relative to each other, with the front end of the cannula pointed upward; PA1 (b) a first conveyor line to transport intermittently the first subassembly jig; PA1 (c) a second subassembly jig having plural hollow cylindrical rests capable of supporting plural pairs of the hub and the cannula in one line by contacting only the hub bonded with the cannula, with the front end of the cannula pointed upward; PA1 (d) a second conveyor line to transport intermittently the second subassembly jig; PA1 (e) a hub-supplying unit provided alongside the first conveyor line; PA1 (f) a cannula-supplying unit provided alongside the first conveyor line; PA1 (g) a hub-cannula-bonding unit, provided alongside the first conveyor line, for adhering the hub and the cannula which has been inserted in the center hole of the hub to a predetermined depth with adhesive; PA1 (h) an adhesive-curing unit, provided alongside the first conveyor line, for heating and drying the hub and the cannula which have been adhered together to form a hub-cannula assembly; PA1 (i) a back-end-coating unit, provided between the first conveyor line and the second conveyor line, for applying silicone-containing-liquid to the back end of the cannula of the hub-cannula assembly; PA1 (j) a handling unit for transferring the hub-cannula assembly by contacting only the hub from the first subassembly jig on the first conveyor line to the back-end-coating unit and further to the second subassembly jig on the second conveyor line; PA1 (k) a back-end-blowing unit, provided alongside the second conveyor line, for supplying air from the front end into the cannula in which silicone-containing-liquid remains so as to blow the remaining liquid out of the back end; PA1 (l) a jig-turn-over unit, provided alongside the second conveyor line, for shifting a direction of the second subassembly jig so as to allow the front end of the cannula to point downward and subsequently upward; PA1 (m) a front-end-coating unit, provided in combination with the jig-turn-over unit, for supplying air from the back end into the cannula and concurrently applying silicone-containing-liquid to the front end of the cannula; PA1 (n) a cap-supplying unit, provided alongside the second conveyor line, for supplying a cap of elongated cylindrical shape having an open end and a semi-spherical closed end to the front end of the cannula, which has been released from the jig-turn-over unit, mounted on the second subassembly jig in upward pointing attitude in such a manner that the cap is supplied downwardly from above with the open end pointed downward so as to allow the cap to cover the front end of the cannula; PA1 (o) a cap-pressing unit, provided alongside the second conveyor line, for pressing the cap covering the front end of the cannula against the hub to form a hub-cannula-cap assembly; PA1 (p) a container-supplying unit, provided alongside the second conveyor line, for supplying a container having an opening at one end to the hub-cannula-cap assembly, in such a manner that the container is supplied downwardly from above with the opening faced downward so as to allow the container to house the hub-cannula-cap assembly; PA1 (q) a container-pressing unit, provided alongside the second conveyor line, for pressing the container housing the hub-cannula-cap assembly against the second subassembly jig; PA1 (r) a container-sealing unit for sealing the opening of the container housing the hub-cannula-cap assembly with sealing sheet by means of heat-sealing, and for stamping out a heat-sealed piece having a predetermined shape from the sealing sheet; and PA1 (s) a container-transferring unit for dismounting the hub-cannula-cap assembly from the second subassembly jig on the second conveyor line and for delivering the hub-cannula-cap assembly to the container-sealing unit.
Hitherto, those work steps are performed in a manufacturing line similar to a conventional one for an ordinary injection needle having no sharp bevel projecting inside the hub, with assistance of manual works as occasion demands. However, there are drawbacks of undesirably low work efficiency and impediment to a laborsaving attempt.
The present invention was made in view of the drawbacks of the conventional method and apparatus for manufacturing the injection needle, and an object of the present invention is to provide a novel method and apparatus of manufacturing the injection needle in an efficient and laborsaving manner.